Here, the valve/pinion is...
Here, the valve/pinion is pushed into place, meshing it with the rack teeth. To ensure the whistle notch is in the correct position, the pinion must not be off by even a single tooth on the rack. If it is, the valve is pulled out and carefully reinstalled—a process repeated until the alignment is perfect.
With the pinion correctly...
With the pinion correctly positioned, the rack bushing and adjuster spring are greased and lubed, respectively, and reinstalled.
The adjuster is reinstalled,...
The adjuster is reinstalled, and the preload is set. That’s done by tightening it to 10 Newton meters and backing it off 60 degrees. After that, the fastener is tightened to hold the adjuster in place.
Reassembly wraps up with the...
Reassembly wraps up with the installation of the cleaned-and- inspected hydraulic lines. Again, an accident may damage them, but unlike the housing and rack shaft, that doesn’t necessarily mean “game over.” Turn One has the capability of having new lines constructed.
The fully assembled rack-and-...
The fully assembled rack-and- pinion unit is put on Turn One’s unique test dyno, which is used to perform a series of functionality inspections. These include basic leak checks at the seals, a pressurized test for internal leaks, and a “pressure effort” test on the valve, which involves “turning” the rack back and forth. In all, each rack spends about 20 minutes on the dyno.
After successfully passing...
After successfully passing all the tests and inspections on the dyno, the tie rods are reattached to the rack and new boots are installed.
Here’s the rebuilt and refurbished...
Here’s the rebuilt and refurbished C4 rack-and-pinion assembly, ready to provide years more service on the street or track. Considering C4 rack-and-pinion units are no longer manufactured, Turn One’s service is downright cheap at about $200.
The name Saginaw is synonymous with steering systems in classic GM vehicles. The facility—yes, located in Saginaw, Michigan—was founded more than 100 years ago and has undergone a number of name and management changes over the years, but it still produces steering components. It has also produced axle systems and adjustable steering columns.
The original works was founded in 1906 by three men with last the last names Jackson, Church, and Wilcox; they called the company Jacox. Buick bought the Jacox facility in 1909. It was separated from Buick in 1917 and renamed the Jackson, Church, and Wilcox Division, becoming GM's first parts-manufacturing arm. The name was changed to Saginaw Product Company in 1919 and to Saginaw Steering Gear Division in 1928. The brand name of the products was changed from Jacox to Saginaw in 1930. In 1985, the division's name was shortened to Saginaw Division.
During the early 1990s, the division was folded into GM's Automotive Components Group, which in 1995 became Delphi Automotive Group when it was spun off from General Motors. A decade later Delphi entered bankruptcy, and by 2008, it looked like the steering business was to be sold to a private equity firm; however, the deal fell apart. GM stepped in and got back into the steering business, renaming it Nexteer, but it didn't stay in for long. In the spring of 2010, GM sold Nexteer to an entity backed by the Chinese government.
A More Efficient Pump
One of the steering-system afflictions on C4, C5, and C6 Corvettes is power-steering fluid that overheats, which damages the pump. That can happen in severe conditions, such as racing. Turn One offers replacement pumps for these cars that require less engine power to operate. That reduces the load on the pumps, which helps keep the fluid from boiling. The pumps are simple replacements for their respective steering systems, and for the C4 enthusiast sending in his race-damaged rack-and-pinion for a rebuild, partnering it with one of the new, more efficient pumps makes a lot of sense.